1. Field of the Invention
This invention relates to a composite integrated circuit device constructed by forming and integrating various types of electronic elements on a semiconductor chip and effectively used as a power integrated circuit.
2. Description of the Related Art
A monolithic semiconductor integrated circuit is formed by integrating transistors, resistors, diodes and the like in a 2-dimensional fashion on a silicon substrate. However, when such an integrated circuit is used as a power conversion circuit such as an inverter, it is difficult to make an output element with large current capacity and high withstand voltage and form the output element together with another element on one chip. Further, it is impossible to integrally form capacitors and inductances which are generally required for the power conversion circuit on a silicon chip. For this reason, in the prior art, a hybrid integrated circuit has been used as this type of power integrated circuit. However, since the hybrid integrated circuit is constructed by mounting various types of semiconductor element chips, resistors, capacitors and the like on a print circuit board or the like, problems that the occupied area increases, the wiring capacitance increases, the assembling process becomes complicated and the like occur. Further, there occurs a problem associated with radiation of a large amount of heat caused by high integration.
As described above, when the power integrated circuit is constructed by using the conventional integrated circuit technology, it is difficult to enhance the current capacity and withstand voltage of the output element in a monolithic integrated circuit and therefore a problem that the occupied area and the wiring capacitance may increase will occur in a hybrid integrated circuit, and in either case, a serious problem associated with heat radiation occurs.